[PATCH 1/3] rust: add `num` module with `PowerOfTwo` type

[Alice Ryhl]

On Fri, Jun 20, 2025 at 3:59 PM Alexandre Courbot <acourbot at nvidia.com> wrote:
> > Similarly, if they stabilize the `Alignment` one (only) and we end up
> > only using our `PowerOfTwo<T>` for `usize` and those use cases, then
> > we should consider using the upstream one (and adding any/all methods
> > that we need).
>
> `Alignment` is very close to what we need, so I don't see a reason to
> not adopt the same name at the very least.
>
> This reminds me that I should also check whether upstream Rust would be
> interested in `prev_multiple_of` and `last_set_bit`. The docs I've read
> for contributing looked a bit intimidating, with RFCs to write and all.
> Would you have a pointer for where I should start? Maybe a Zulip thread?

If you want to add a new library function, the correct procedure would
be opening an ACP, which is more light-weight than the RFC process:
https://std-dev-guide.rust-lang.org/development/feature-lifecycle.html

RFCs are mainly for much bigger changes.

Alice